YANGON: Thousands of Myanmar anti-coup demonstrators defied a continued military crackdown Sunday, following overnight raids in Yangon in which an official from Aung San Suu Kyi's party was beaten to death and several others were detained.

Myanmar has been rocked by unrest since a February 1 coup ousted civilian leader Suu Kyi from power and triggered a mass uprising opposed to the new military junta.

Wednesday was the deadliest day so far, with the United Nations saying at least 38 people were killed as security forces fired into crowds, shooting some protesters in the head.

The UN rights office also said it has verified at least 54 deaths since the coup -- though the actual number could be far higher -- and more than 1,700 people have been detained.

National League for Democracy party official Soe Win confirmed some officials were arrested in overnight police operations but the exact number is not known.

At least one community leader connected to the ousted NLD government, 58-year-old Khin Maung Latt, was killed during a raid at Pabedan township in Yangon, Tun Kyi, from the Former Political Prisoners Society, said.

"He was beaten and taken in a raid since last night and it seems he underwent a harsh interrogation," he told AFP.

"The dead body is being taken from Mingaladon military hospital and on the way to Yay Way cemetery."

NLD MP Sithu Maung posted on Facebook that security forces last night were also searching for the party's information officer Maung Maung but had been unable to find him.

"Maung Maung's brother was beaten by police and soldiers and his body was held in an upside-down position while he was tortured because there was no one to arrest," the MP said.

State-run media on Sunday warned ousted lawmakers involved in a group called the Committee Representing Pyidaungsu Hluttaw -- which is claiming to be the legitimate elected government -- that they are committing "high treason" and could be sentenced to death or 22 years jail.

The junta has declared group members personae non-grata and says those who communicate with them could face seven years prison.

   **- 'Willing to die' -**

Rallies fanned out across the country with more than seven separate demonstrations in Yangon and at least five in other cities and regional towns, according to Facebook live feeds.

The only reports of serious injuries were a 19-year-old man shot in the jaw and a woman, 56, hit by a rubber bullet in Bagan, a UNESCO World Heritage Site famed for its ancient Buddhist temples.

"One woman was shot with a rubber bullet in her left leg," a rescue team member told AFP, requesting anonymity.

Security forces opened fire near the ancient city at around 9am local time (0230 GMT).

"There was one (19-year-old) man who was shot through the jaw and neck in Bagan," Ko Ko, a member of the Bagan rescue team, told AFP.

Yangon-based activist Maung Saungkha said coordinated protests across multiple cities and areas were part of a two-day general strike.

"We are willing to die for our country," he told AFP.

"This current situation is worse (than the past regime). So do we stay under this condition or do we fight? This time we must fight to win."

A state-run newspaper Sunday urged people not to join the rallies.

"The public should be careful not to get involved in the protests to prevent the future of their children being ruined," the Global New Light of Myanmar said.

The junta also warned civil servants that "they will be fired" with immediate effect from Monday if they continued to boycott work.

In Yangon's North Okkalapa township, protesting took on a musical flavour Sunday with guitarists, drummers and vocalists wearing Suu Kyi t-shirts singing revolutionary songs at an impromptu concert.

"It's important brothers and sisters, let us unite," the crowd sang.

There was also a large turnout in Mandalay -- Myanmar's second biggest city -- where security forces used tear gas, rubber bullets and live rounds in the afternoon against protestors.

Yan Naing from the Mandalay rescue service told AFP that two of his colleagues were shot while driving motorbikes -- one managed to escape but the other was taken away by security forces.

Another woman on a motorbike was also shot and authorities removed her from the scene to an unknown location, he added.

Scores of monks in saffron robes also staged a sit down protest in the city, with signs saying "we don't want a military junta".

That city lost another life Saturday, according to the Assistance Association for Political Prisoners, which reported that 21-year-old man Naing Min Ko had died after being shot in the leg and beaten by security forces the previous day.

The monitoring group also said a group connected to the military-backed Union Solidarity and Development Party was responsible for two deaths on Saturday morning in the Magway region -- a 17-year-old and a NLD party official.

In neighbouring Thailand, thousands of Myanmar migrant workers rallied outside the United Nations Office in Bangkok on Sunday calling for intervention. Many waved their country's flag and held photos of Suu Kyi in the air.—AFP